SDG&E warns 170,000 customers they could lose power in Thursday's 'extreme' windstorm

San Diego Gas & Electric says it has notified 170,000 customers that they’re at risk of losing power on Thursday when “extreme” Santa Ana winds explode through the region, especially the mountains and valleys of East County.

The utility has sent a power generator to Julian, positioned work crews so that they can pounce on outages, and it brought in a heavy-lift helicopter that can drop 2,500 pounds of water on any wildfires that might erupt in the arid back country.

The chopper has about eight times the capacity of other helicopters used to fight wildfires.

SDG&E says it also might be forced to temporarily turn off power in certain areas of the county on Thursday to protect the integrity of the electric system. The company temporarily did that to about 87 customers in the Descanso area earlier in the week.

The National Weather Service says the offshore wills pick up late Wednesday night and accelerate at about dawn on Thursday, with gusts of 80 to 90 mph along some of the peaks in East County.

Other inland areas will be lashed by 35 to 45 mph winds, with spikes to 55 mph, notably in places like Alpine, Pine Valley, Julian, San Diego Estates and Campo.

The winds also will gust 20 to 30 mph on Thursday along the coast, from roughly Point Loma to Camp Pendleton.

“This could be the worst wind storm since the ones that caused about a dozen fires in 2014,” said Alex Tardy, a forecaster at the National Weather Service. “The parameters are the same: The landscape is dry, the winds will be fast and widespread, and the humidity will be really low.

“If a wildfire starts on Thursday it’s going to be a real problem because winds will be blowing all the way to the coast, and we’ll have offshores until the weekend, which drags things out.”

Tardy’s colleagues Stephen Harrison said, “San Diego County will be the windiest place in Southern California, and that could bring problems.”

Much of San Diego County will remain under a red flag fire weather warning until 6 p.m. on Saturday, and a high wind warning will be in place for most of the rest of the region through late Friday afternoon.

Forecasters say that no significant rain is expected in San Diego County through mid-December.